Rewrite prettyprint code.
Show pretty-printed code on single image page.

* New element on the page [single_image_page.ejs].
* Updated Javascript to fill in and set width [imagepage.js]
* Style the new element [singleImage.css]
Merge branch 'master' of github.com:GlimmerLabs/MathOverImages
Minor cleanup of view challenge.
Style for GUI element in challenge.
Progress toward separate GUI objects.

* We can now put all of the mistgui*.js code in the head.
* We initialize the stage with initializeStage(containerName).
Merge branch 'master' of github.com:GlimmerLabs/MathOverImages
Minor comment fix.
Minor comment fix.
Minor comment fix.
Restyle pages slightly.

* Got rid of the annoying "margin: 80px" that was in the main style sheet
  and which made stuff harder..
* Did my best to incorporate that change in all the remaining pages.
Merge branch 'master' of github.com:GlimmerLabs/MathOverImages